Ey French Gramma question..?

I jus got Rosetta stone, and has NO french background, and on the first lesson i learned alot but to shorten this up, whats teh diference between: "les, une, des, Ils, un" or whatever, im thinking "Ils" is like when "they" are doing some action like "Ils listent" ........ but they also gave "elles cuisine".. soo hellp please?